Nov 2023
Abstract
The term “fiber” from a geometrical perspective is a thin and elongated structure made of any material. Nature uses it for various applications e.g., plant fibers which are thick-walled cells act as support to provide strength to the plant tissues, extra-cellular matrix of the connective tissue uses a network of various protein fibers to regulate the cellular functions, and dietary fiber which primarily consist of polysaccharides such as cellulose helps in muscle movements in the intestine. Textiles use both natural and synthetic fibers such as cotton and nylon, respectively, which can be spun into woven forms whereas glass and carbon fiber reinforced plastics are widely used in structural applications. In this talk, I will give a brief overview of the importance of fibers and how they are synthesized naturally and synthetically. Cotton candy is a classic example of melt spinning which everyone can relate to. Using similar concepts, ultra-thin fibers can be spun using electrospinning which has evolved into a very versatile yet simple process for making polymers, ceramic and carbon nanofibers. With diameters in nanoscale, they offer unique opportunities to develop composite and hybrid materials which can bypass traditional material performance trade-offs. Some of our work on understanding the size-dependent mechanical response of single polymer and carbon nanofiber will be presented. Moreover, these nanofibers act as an excellent functional support for hybrid materials involving functional metal and oxide nanoparticles and in-situ grown nanotubes for photo and electro-chemical applications. For example, metal nanoparticles encapsulated at the tips of carbon nanotubes grown over carbon nanofibers has shown excellent performance for electrocatalysis e.g., oxygen and hydrogen evolution reactions for water splitting as well as oxygen reduction reactions for metal-air batteries and fuel cell applications. Similarly, forming photocatalytic heterojunctions with titania nanofibers as base material is demonstrated as a potential route to self-cleaning filtration membranes for removing dyes, treating heavy metals, and degrading pathogens. Examples of these materials will be presented with emphasis on their structural, chemical and morphological characteristics and their relation to performance.
Bio
Dr. Salman N. Arshad is currently serving as an Associate Professor within the Department of Chemistry and Chemical Engineering at the Syed Babar Ali School of Science and Engineering, Lahore University of Management Sciences (LUMS). His academic journey began with a bachelor’s degree in Metallurgy and Materials Engineering from the GIK Institute of Engineering Sciences and Technology in Pakistan. Subsequently, he pursued his master’s degree in Materials Science and Engineering at the Korea Advanced Institute of Science and Technology (KAIST) in South Korea. During his time at KAIST, he pioneered innovative bottom-up techniques for synthesizing carbon nanotube-reinforced metal and ceramic nanocomposite materials, resulting in remarkable morphologies and properties recognized by two publications in Advanced Materials.
Following this, Dr. Arshad worked as a Research Associate at GIK Institute, where he not only taught materials engineering courses but also designed laboratory courses. He later embarked on a Fulbright Fellowship journey to the University of Illinois at Urbana-Champaign (UIUC), earning another master’s in aerospace engineering and a Ph.D. in Materials Science and Engineering. At UIUC, his research revolved around optimizing polymer and carbon nanofibers with tailored surfaces to enhance the strength and toughness of structural composite materials. The work was published in Carbon and Polymer as well as earned a US Patent. His work extended to the development of bulk nanostructured alloys via high-temperature severe plastic deformation, with grain and second-phase precipitate sizes reaching the nanometer scale, which was published in Acta Materialia and Scripta Materialia.
Dr. Arshad currently leads the Functional Nanofibers research group at LUMS, focusing on designing and synthesizing nanofibers for their application as functional supports in the development of efficient photo- and electro-catalysts. This involves fine-tuning the electronic, structural, and chemical characteristics of the materials to enhance their catalytic performance. Examples of this work include contributions to the fields of oxygen evolution and hydrogen evolution reactions in water splitting, as well as the oxygen reduction reaction in rechargeable metal-air batteries and photo-catalyzed redox reactions for environmental remediation. Moreover, the group also explores tuning of physical and chemical nature of the interface in nanofiber reinforced epoxy nanocomposites and its effect on mechanical and functional performance. Recent research findings from Dr. Arshad's group have been published in esteemed peer-reviewed journals such as ChemCatChem, ACS Applied Nanomaterials, Journal of Environmental Chemical Engineering, and Polymer Composites, among others.